Die-stock.



L. F. HART.

DIE STOCK.

APPLICATION FILED AUG-2,5, I910.

1 1%$,9@@m Patented. June 22, 1915.

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L. F. HART.

v DIE STOCK. APPLICATION FILED AUG.25 I910.

.1,M3,960m Patented June 22, 1915.

3 SHEETS-SHEET 3.

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LOUIS F. HART, OF CLEVELAND, OHIO, ASSIGNOR TO THE HART MANUFACTURING COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

DIE-STOCK.

Specification of Letters Patent.

Patented June 22, 1915.

Application filed August 25, 1910. Serial No. 578,850.

To all whom it may concern Be it known that I, LOUIS F. HART, a citizen of the United States, and a resident of Cleveland, county of Cuyahoga, and State of Ohio, have invented a new and useful Improvement in Die-Stocks, of which the following is a specification, the principle of the invention being herein explained and the best mode in which I have contemplated applying that principle, so as to distinguish it from other inventions.

The present invention, relating as indicated to die stocks, has more particular regard to die stocks of the type widely known on the market as Duplex stocks, the general features of which are illustrated in U. S. Patents Nos. 263,402 and 686,221. Such die stock is characterized by having a body member to which the handle, ratchet, or equivalent operating means, are attached and in which are adjustably, removably held a plurality of chaser dies that are utilized to cut the thread. The latter are positioned in such body member by a cam plate rotatably mounted thereon and adapted to be locked in various positions by means of a lock plate. Guide jaws, or blocks, are similarly movably mounted in such body member and, like said die blocks, are held in desired position by a cam plate that is locked by a second, locking plate.

The object of the present invention is the provision of improved means for adjusting, locking and releasing the cam plates in the type of die stock just described, whereby the chaser dies and the guide jaws are respectively positioned.

A further object is the provision of improved means for preventing undue rotation of the first of said cam plates in a direction to withdraw the dies.

In certain of these particulars the present invention may be regarded as an improvement on the structure described and claimed in my co-pending application filed February 21, 1910, Serial No. 545,066. The means for accomplishing the foregoing and related ends will be hereinafter fully described and particularly pointed out in the claims.

The annexed drawings and the following description set forth in detail certain mechanism embodying the invention, such disclosed means constituting, however, but one of various mechanical forms in which the principle of the invention may be used.

In said annexed drawings, Figure 1 is a front elevation of a die stock embodying my present improvements; Fig. 2 is a vertical axial section thereof; Fig. 3 is a rear elevatron of the same; Fig. 4: is a bottom plan v 1eW thereof; Fig. 5 illustrates a modification 1n construction of a detail; Fig. 6 illustrates a centering jaw and adjusting screw therefor that forms another feature; Figs. 7 and 8 illustrate in detail a catch screw and washer forming features of the invention; Fig. 9 shows a modification as to yet another detail; and Figs. 10, 11 and 12 illustrate in diagrammatic fashion the different operative positions of the catch with respect to the cam-plate which it is designed to hold against rotation.

In view of the description already afforded of the general class of die stocks to which the present improved structure relates, the more familiar features of the latter need only be briefly noted. The body member comprises, in effect, simply a coredout head 1, the outer portion 2 of which is provided with sockets 3 adapted to receive handles 4 for operating the stock; the inner portion of which is in the form of a sleeve 5 that projects beyond such outer portion at each end. Such body is provided with two sets of openings, that extend through such inner sleeve portion and are respectively adapted to receive, and constitute guides for, the chaser dies 6 and the guide jaws, or blocks, 7. Four such dies are shown and three guide jaws, with corresponding openings therefor, but it will be understood that the number, both of the dies and of the guide jaws, may be varied, should occasion demand, and a corresponding variation made in the number and location of the openings in the body. The cam plate, or ring 8, for positioning the guide blocks, is rotatably mounted upon the rearwardly extending end of the sleeve portion 5 of the body, while the die blocks are similarly positioned by means of a cam plate. It is to the means newly provided for adjusting and retaining these respective cam plates in desired position that attention is herein desired.

The cam plate 8 is held in place on the sleeve by a retaining ring 10, threaded on the sleeve and locked in place by a set screw 11, so as to retain such plate against end- Wise movement, while still permitting it to rotate. For the purpose of thus rotating the cam plate, as well as holding the same in adjusted position, means, directly cooperating with one of the guide jaws, are provided. Preferably such means comprise a screw 12 with a winged head, that is threaded into the outer projecting end of one of the jaws. The body of this screw is formed with an encircling slot 13 adapted to fit in a recess formed in one side of a plate 14, that is secured, as by a screw 15 in two slotted ears or lugs 16 projecting from the body of the die stock. The cam grooves in the plate 8, that engages with the centering jaws, instead of being made as little eccentric as possible (this being the prevailing construction), are'of a relatively sharp degree of eccentricity. By this construction, 1 have found that rotation of the plate may be readily effected by drawing in or out one of the jaws, as by means .of the adjusting screw just described. Not only may such jaw be thus positioned as desired, but, by reason of the plates rotation, the two remaining jaws will be given corresponding positions in their respective slots. By this construction an extremely simple and quite effective mode of adjustment for the centering jaws of the die stock is provided.

' The pins 17 in the guide jaws which thus engage with the grooves of the cam plate are preferably formed separately from the blocks and then press-fitted in suitable holes in the sides thereof. Of such pins, the one on the main, or actuating, jaw operated by screw 12 is made with a head 18 somewhat larger than the corresponding hole and when the shank has been fitted in place, the shoulder between it and the head rests solidly against the surface of the block. This head is furthermore initially made of a diameter greater than that of the cam groove in which it is desired subsequently to fit. Its front side, that is the one disposed toward the center of the die stock, is subsequently milled off to present a broad surface 19 against the corresponding edge of the cam groove and angularly disposed to thus bear against the same irrespective of the position of the cam plate about its axis. The width of the head transversely of the groove is, however, left substantially equal to such groove, so that while the contacting face of the pin, which bears the thrust when the stock is in operation, is formed to present a broad bearing face, the opposite side of the pin will on the contrary have merely a line contact with the corresponding face of the groove. At the same time the projecting shoulder on the outer side of the pin serves to brace the latter against the strain imposed upon it.

Cam-plate 9, which engages with and serves to position the die blocks, is held in place on the sleeve 5 by a retaining ring 20 threaded thereon and locked in place by a set screw 21 just as in the case of the cam plate for the guide jaws. At a convenient point about its periphery, the body of the stock is provided with two transversely alined ears or lugs 22, in which is rotatably held a capstan headed screw 23, such screw being secured in the lugs in question by means of a retaining nut 24 threaded on its end. By means of the disposition of said lugs, this screw, it will be seen, is alined with the direction. of movement of the camplate relatively to the body of the stock or, as it may otherwise be expressed, the axis of said screw lies parallel to the plane of such relative movement. The threaded end of the screw projects a short distance beyond the nut and is then upset sufiiciently to prevent such nut from being removed. Between the nut and the adjacent lug 22, I interpose a spring washer 25, of the kind clearly shown in Fig. 5, so that while, by rotation of the nut, the screw may be loosened sufficiently in its bearings in the lugs to permit of its rotation therein, it will, nevertheless at all times be held with its head snugly against the lug adjacent to such head. By tightening up nut 9.4-, how-. ever, the screw is securely locked in any desired position. Threaded upon and oscillatory about said screw intermediate between the two lugs, is a catch 26, of the form shown in Fig. 2, which catch is capable of transverse adjustment within the space defined by the two lugs by rotating the screw in one direction or other, as will be obvious. The forward end of said catch is designed to engage with a suitable notch 27 formed in a boss, or radially extending portion, 28 of the cam plates periphery, the preferred form of this notch being shown in detail in Figs. 10, 11 and 12. As shown in such figures, as also in Fig. 1, but one notch is utilized, but in Fig. 7 a cam plate having a plurality of notches is illustrated. It is designed that the range of adjustment of the catch transversely of the die head shall be suflicient to provide for the radial adjustment of any set of dies within the range of diameters that is desirable for certain use of such dies. More than one notch, however, is provided where a wider range of adjustment is desired.

As will be observed upon reference to the front elevational view of cam plate 9 and catch 26, shown in the detail just referred to, the two sides of the catch are not similarly formed, the one that is under pressure during the cutting operation, (as indicated by the arrow) being formed at a considerably sharper angle, than the other, in fact on a line substantially parallel with a radius to the axis of the die stock; whereas the other side slants at an angle to such radius approximately as shown. The respective sides of the slot similarly differ in their degree of slant to correspond with the sides of the catch, the slant of the sides of the slot being however greater than that of the catch for the reason that while the latter is adjusted in a tangential line the notch of course moves on a circle; its walls are accordingly formed to have substantially a surface contact with the sides of the catch in the extreme positions of the latter within its range of adjustment, as illustrated in Figs. 9 and 11 respectively. At any intermediate position of adjustment, however, the catch will have simply a line contact at the bottom of the notch with the respective sides of the latter, as illustrated in Fig. 10.

By reason of the above described conformation of the notch and engaging catch, the latter will tend to remain seated even under the strain of operation, the angle of that face of the notch which is then under pressure being within the angle of repose. But upon starting to lift the catch, the latter is immediately freed from contact with the notch, so that the plate may be released with but little effort even while the dies still tightly grip the work. To further facilitate such release the thread on the screw 23 that receives said catch is made lefthanded, so that a slight lateral displacement of the catch occurs when it is turned up.

In order to retain the catch in its position of engagement with the notched cam plate, I provide a spring-pressed plunger 32 radially movable in the die head and adapted to engage a transverse V-groove 29 in the edge of the catch body. This plunger and groove are relatively so disposed that, in the normal position of the catch shown in Fig. 2, the former is ofiset a trifle to the rear of the latter. Such plunger, which has a corresponding beveled end (either of wedge shape or of the conical form illustrated), will accordingly engage the face of the groove farthest from the catch proper and thus operate to force the latter into the notch of the cam plate. This same plunger in the raised position of the catch is de signed to exert suflicient pressure against the body of the latter to retain such catch against movement, except at the instance of the operator. In place of such springpressed plunger other means may be utilized to thus cooperate with the catch. For example, as illustrated in Fig. 8, a simple flat, or leaf, spring 30, secured to the body of the die stock, may be so disposed as to press against the body of the catch with its free end. .By way of further variation such catch body is here shown with a lug or transverse rib 31, in place of the V-groove, and the spring is formed so as to engage with such e5 rib.

The dies 6, it will be observed, are shown as threaded at both ends, this being a desirable construction in stocks of the class in hand. In order to facilitate their adjustment for cutting on any particular diameter of pipe, I provide graduations 36 on the narrower sides or edges of said dies, or at least on one edge of the same, and arrange an index on the body of the stock, preferably in the form of a boss 35 adjacent to such die (Fig. 1), Wherewith the graduation marks may be brought into register. Such registration is arrived at approximately by turn ing the cam plate, through its handle, but is more exactly effected, finally, by adjustment of the screw 23 after the catch 26 has been brought into engagement with the proper notch 27 on the cam plate.

The dies may be removed for the purpose of exchange or replacement, by rotating the cam plate until the pins in the dies (only one of such pins being shown in Fig. 1, in order to avoid confusion), are brought into the outer ends of grooves 32. Normally the cam plate is limited in its movement in the direction to thus withdraw said dies, by engagement of a flat spring 33, mounted on the body of the stock, with a lug 34- on the edge of the plate, Figs. 1 and 2, the spring projecting far enough forwardly from the body to engage one face of such lug. While the latter has one face thus formed for engagement, its other face slopes so as to permit a return movement of the plate past the spring without interference. When it is desired to withdraw the dies, it suflices simply to raise the spring enough to allow the lug to pass.

The advantages of my improved means for adjustably securing the cam plate 9 to the body of-the stock, in the manner just described, should be apparent without particular description. Not only may the plate be thus secured in adjusted position for the cutting of threads of any particular diameter, as indicated on the sides of the dies, but the retention of the plate in such position is assured by reason of the positive locking action of the catch 26. At the same time a fine degree of adjustment of the dies is permitted so as to cut over or under any particular size, as is at times desirable, such adjustment being made exact instead of ap proximate only, as where the handle is relied on entirely for manipulating the cam plate. In order, moreover, to release the die stock from the work when, as at the end of a cut, the dies are screwed on far enough, it suffices merely to turn back the catch, thus disengaging the cam-plate. The grooves in the latter are pitched somewhat more steeply than in the prevailing constructions of diestoclr, so that upon such disengagement of the plate, the pressure of the dies is efiective to rotate the same sufliciently to relieve any binding or strain between the tool parts.

If the tool be now given a further turn, such dies will clean the threads nicely but do no further cutting. Thereupon the cam plate is turned as far as the stop spring 33 will 7 permit, whereby the dies are withdrawn clear of the work so that the tool may be directly removed. Upon beginning a new cut, the dies may be returned to their identical former positions by simply restoring the cam-plate to its former position, viz., that in which the latch may be drawn again into engagement with the notch on the cam-plate wherewith it previously engaged. WVhile, as indicated, any undue rotation of the camplate is prevented by the retractable stop spring 88, the latter may be raised out of the way should it be desired to actually remove the dies from the tool, as has been previously explained.

It may be remarked in conclusion, that, of course, the several novel features of diestook construction exemplified in the tool herein described may be utilized separately, or in'combination with other, different features, if desired. This applies particularly to the mounting of the centering jaws, and to the mechanism for operating the same.

Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the mechanism herein disclosed, provided the means stated by any of the following claims or the equivalent of such stated means be employed.

I therefore particularly point out and distinctly claim as my invention 1. In mechanism of the character described, the combination of a body member; dies movable in said member; a cam-member, said body member and cam-member being relatively movably secured together and the latter being adapted to position said dies in the former, upon such relative movement; a screw rotatably mounted on one of said members about an axis lying parallel to the plane of such relative movement between said members, the other member having an engaging element; means adapted to hold said screw against rotation; and a catch having threaded engagement with said screw and adapted to engage said element to secure said members against relative movement.

2. In mechanism of the character described, the combination of a body member; dies movable in said member; a cam-member movably secured to said body member and adapted to position said dies therein; a screw rotatably mounted on one of said members about an axis lying parallel to the plane of such relative movement between said members, the other member having its periphery notched; a lock-nut on said screw adapted to hold the same against rotation; and a catch having threaded engagement with said screw, and adapted to engage the notch in said last named member.

3. In mechanism of the character described, the combination of a body member; dies movable in said member; a cam-plate rotatably secured to said member and adapted to position said dies therein, said cam-plate having its periphery notched; a screw rotatably mounted on said member about an axis transverse to that of said camplate; means adapted to hold said screw against rotation; and a catch having threaded engagement with said screw and adapted to engage a notch in said cam-plate.

4. In mechanism of the character described, the combination of a body member; dies movable in said member; a cam-plate rotatably secured to said member and adapted to position said dies therein, said camplate having its periphery notched; a screw rotatably mounted on said member about an axis transverse to that of said cam-plate; a lock-nut on said screw adapted to hold the same against rotation; and a catch having threaded engagement with said screw and adapted to engage a notch in said camplate.

5. In mechanism of the class described, the combination of a body member having transversely alined, spaced lugs on one side; dies movable in said member; acam-plate rotatably secured to said member and adapted to position said dies therein, said camplate having its periphery notched; a screw rotatably mounted in the lugs on said member with a head adapted to rest against the one such lug and an end projecting through the other lug; a lock-nut on such projecting end of said screw; a spring washer interposed between said nut and the adjacent lug; and a catch having threaded engagement with said screw and adapted to engage a notch in said cam-plate.

6. In mechanism of the character described, the combination of a body member; dies movable in said member; a cam-member rotatably secured to said body member and adapted to position said dies therein, one of said members having its periphery notched; and a catch pivoted on the other of said members about an axis transverse to the axis of rotation of said cam-member, said catch being adjustable longitudinally of its axis, and being adapted to engage the notch in said first-named member, the sides of such notch being formed so as to have a surface contact with the corresponding sides of said catch in approximately the extreme transverse positions of the latter respectively, and only a line contact in intermediate positions thereof.

7. In mechanism of the character described, the combination of a body member; dies movable in said member; a cam-member rotatably secured to said body member and adapted to position said dies therein, one of said members having its periphery notched; and a catch pivoted on the other of said members about an axis transverse to the axis of rotation of-said cam-member, said catch being adjustable longitudinally of its axis and being adapted to engage the notch in said first named member, the sides of said catch being beveled, and those of such notch being also beveled, but to a greater extent so as to have a surface contact with the corresponding sides of said catch in approximately the extreme transverse positions of the latter and only a line contact in intermediate positions thereof.

8. In mechanism of the character described, the combination of a body member; dies movable in said member; a cam-plate rotatably secured to said member and adapted to position said dies therein, said cam-plate having its periphery notched; and a catch pivoted on said member about a fixed axis transverse to that of said cam-plate, said catch being adjustable longitudinally of its axis and being adapted to engage a notch in said cam-plate, the sides of such notch being formed so as to have a surface contact with the corresponding sides of said catch in approximately the extreme trans verse positions of the latter respectively and only a line contact in intermediate positions thereof.

9. In mechanism of the character described, the combination of a body member; dies movable in said member; a cam-plate rotatably secured to said member and adapted to position said dies therein, said cam-plate having its periphery notched; and a catch pivoted on said member about a fixed axis transverse to that of said camplate, said catch being adjustable longitudinally of its axis and being adapted to engage a notch in said cam-plate, the sides of said catch being beveled and those of such notch being also beveled but to a greater extent so as to have a surface contact with the corresponding sides of said catch in approximately the extreme transverse positions of the latter and only a line contact in intermediate positions thereof.

10. In mechanism of the character described, the combination of a body member;

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dies movable in said member; a. cam-plate rotatably secured to said member and adapted to position said dies therein, said camplate having its periphery notched; and a catch pivoted on said member about a fixed axis transverse to that of said cam-plate, said catch being adjustable longitudinally of its axis and being adapted to engage a notch in said cam-plate, the sides of said catch being beveled unequally, the side under pressure during operation being least inclined, and the sides of such notch being also beveled but to a greater extent than the corresponding sides of said catch so as to have a surface contact with the latter in approximately the extreme itransverse positions of said catch and only a line contact in intermediate positions thereof.

11. In mechanism of the character described, the combination of a body member; dies movable in said member; a canrplate rotatably secured to said member and adapted to position said dies therein, said camplate having its periphery notched; a screw rotatably mounted on said member about an axis transverse to that of said cam-plate; and a catch having threaded engagement with said screw, the thread on the latter inclining in a direction to tend to relieve said catch, when turned upwardly, from the pressure of the cam-plate.

12. In mechanism of the class described, the combination of a body member; a camplate rotatably secured to said member and adapted to position said dies therein, rotation of said cam-plate in a clock-wise direction serving to retract the same and the periphery of said cam-plate being notched; a screw rotatably mounted on said member about an axis transverse to that of said cam-plate; and a catch having threaded engagement with said screw, the thread on the latter being left-handed so as to relieve said catch, when turned upwardly, from the pressure of the cam-plate.

Signed by me this 23rd day of August, 1910.

LOUIS F. HART.

Attested by- ANNA L. GILL, JNo. F. OBERLIN.

Copies of this patent may be obtained for five cents each, by addressing the Gommissioner of Patents,

Washington, .D. G. 

